st-Ht31 is a stearated and cell permeable version of the peptide Ht-31, which inhibits the interaction between the RII subunits of cAMP-dependent PKA and A-kinase anchoring protein (AKAP). The sequence of st-Ht31 is derived from human thyroid RII anchoring protein Ht31, comprising residues 493-515, and is the minimum region of Ht 31 required for RII binding. Disruption of the AKAP-PKA interaction by st-Ht31 alters human airway smooth muscle proliferation and enhances contractile force generation with upregulation of the contractile protein alpha-sm-actin. st-Ht31 also increases cytosolic PKA activity and is able to reverse foam cell formation and restore metabolic health in otherwise dysfunctional macrophages.
